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REAL-TIME PERFORMANCE MONITORING & OPTIMIZATION AT DUBAI
ELECTRICITY & WATER AUTHORITY’S COMBINED CYCLE POWER AND
DESALINATION PLANT IN DUBAI
Dr. Jeff Parmar & Mr. Matt Auer
General Physics, UK
Mr. Hiroyuki Ichikawa
Toshiba, Japan
Mr. Daming Yang & Mr. Shawn Whitecar, P.E.
General Physics Corporation, USA
_________________________________________________________________________
EtaPRO™, EPReporter™, EPTrendSetter™, EPAlert™, and Virtual Plant™ are trademarks of General Physics Corporation.
POWER-GEN MIDDLE EAST 2010 October 4- 6, 2010 Doha, Qatar
ABSTRACT
This paper describes a state-of-the-art real-time
performance monitoring and optimization system
installed at the Dubai Electricity and Water
Authority‟s (DEWA) Jebel Ali L1 Combined Cycle
Power Plant located in Jebel Ali in Dubai.
This plant provides gross electrical output of 796,700
kW and 70 million gallons (317,500 m3) per day of
potable water at design reference conditions of
ambient temperature of 50°C, relative humidity 34%
and ambient pressure of 1.0132bar to meet the needs
of Dubai‟s rapidly expanding economy. The Jebel Ali
L1 facility was a direct result of project agreements
for DEWA‟s Power and Water Production, which
were signed in Dubai in 2005 between Toshiba who
are the Engineering Procurement and Construction
Contractor of power plant package. The gas turbines
are supplied by General Electric and are of Frame
9FA.
The system provides real-time indication of power
and water plant Key Performance Indicators (KPI‟s),
including actual and expected values. A first
principles thermodynamic model integrating the
power and desalination processes was developed to
support both real-time and off-line “what-if” and
optimization strategies. The optimizer is fully
interactive at the desktop and allows engineers and
production managers to investigate any of over 50
different operating modes the plant is capable of
supporting. In addition to monitoring and modeling
plant processes, the system provides routine
archiving and reporting of all pertinent parameters.
The client/server software architecture provides end-
users access to the system from client/server
workstation.
By monitoring important performance parameters such
as gas turbine corrected power, HRSG and steam
turbine efficiencies, and target (or expected) steam
header pressure, plant performance can be optimized
wherever possible, and problems identified at an early
stage.
With an accurate measurement of plant performance
continuously compared with a proven benchmark,
plant personnel are able to better operate their
facilities in a competitive market, as well as ensure
that water and power production has been fully
optimized. This paper describes the design
methodology and installation process of the on-line
monitoring system, as well as pitfalls associated with
establishing achievable performance benchmarks.
Key features of the optimization system along with
the strategy employed for technology transfer to plant
staff are also discussed.
INTRODUCTION
The Jebel Ali L1 facility arose from project
agreements between DEWA and Toshiba‟s which
were signed in Dubai. The Jebel Ali L1 facility is a
nominal 800 MW combined cycle power and
desalination plant developed on a Build and Transfer
(BT) basis between a consortium of Toshiba,
Mitsubishi Corporation, Fisia Italimpianti, Alstom,
Doosan Heavy Industries and Lahmeyer
International. To maximize the profitability and
optimize water and power production, a state-of-the-
art on-line performance monitoring system was
installed to alert and advise the operating and
management staff of any deviation from the optimum
levels of performance. By monitoring important
performance parameters such as gas turbine corrected
power, HRSG and steam turbine efficiencies, and
target (or expected) condenser pressure, plant
POWER-GEN MIDDLE EAST 2010 October 4- 6, 2010 Doha, Qatar
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performance can be optimized wherever possible, and
problems identified at an early stage.
The Jebel Ali L1 Combined Cycle Power Plant
consists of three blocks each with three GE Frame
9FA gas turbines (GTs), three Doosan Heat Recovery
Steam Generators (HRSGs) and two Toshiba steam
turbines (STs). The HRSGs are equipped with
supplementary or duct firing. There are two auxiliary
boilers which can supply steam to the steam turbines
for power production and steam for desalination
plant. The desalination plant has five distillers of sea
water fed by the steam produced from the HRSGs
and the auxiliary boilers The GTs can run in simple
cycle operation with by stacks installed at the exhaust
of each of the GTs. The gas turbines and the auxiliary
boilers are capable of firing light distillate oil which
is normally used as back up fuel in the event when
the natural gas fuel is not available or for other
operational reasons.
The Jebel Ali L1 Water Plant has been designed with
a capacity of 317,500 m3/day water produced by five
desalination units. The desalination units are of the
multi-stage flash type (MSF-type). The desalination
units are designed for a distillate production rate of
14 Million Gallons per Day (MIGD) (63,500 m3/day)
each, operating with suitable anti-scaling additive for
the make-up seawater at a top brine temperature of
108 °C and a seawater temperature range from 15 °C
to 35 °C.
During normal operation the plant is operated as a
single entity. This means that the three GTs, the three
HRSGs, the two STs, are interconnected in such a
way that “block concept” is not foreseen and any
equipment can be operated from any operating station
in the Central Control Room. The main steam
headers and the feed water headers operate as
interconnected systems.
The EPC Contractor, Toshiba in collaboration with
General Physics Corporation (GP) installed the on-
line performance and condition monitoring system,
EtaPRO™ supplied by GP. The main objectives of
installing the EtaPRO System are to readily identify
equipment performance deficiencies, cycle isolation
problems, instrumentation problems in timely manner
and above all, to optimize the generation of
electricity, water production and the steam for
cogeneration purposes. The installed system monitors
real time performance, archives process data and
calculates results, and automatically report on key
performance indicators. The installation of EtaPRO
will also be utilized to maximize the plant
profitability by alerting and advising the plant
operating and management staff of performance
improvement opportunities.
IMPROVING PLANT PERFORMANCE
The main purpose of the on-line performance and
condition monitoring system is to readily identify
equipment performance deficiencies, cycle isolation
problems or instrumentation problems on a real-time
basis. This requires the functionalities shown in
Figure 1.
Figure 1. Performance Improvement Functions
Real-time Monitoring (EtaPRO™ System). Plant
performance cannot be improved or maintained
unless it is measured and quantified in a consistent
and routine manner. This function is performed by
the EtaPRO System at Jebel Ali L1 Power Plant. The
EtaPRO System is a client/server application that
provides a comprehensive library of pre-engineered
performance calculations applicable to individual
equipment as well as the overall plant. Calculations
are customized to the requirements of the Jebel Ali‟s
specification. Process data required to support
calculations is acquired from the Toshiba‟s installed
Distributed Control System (DCS) at Jebel Ali L1.
The installed DCS system is TOSMAP-DS™. The
TOSMAP-DS utilizes the state-of- the-art
technologies which realize high-level controllability,
human friendly man-machine interface and versatile
communication with other system.
Trending (EPTrendSetter™). Trending of data is an
effective way to analyze aspects of plant behavior
and performance which cannot be perceived from the
minute-to-minute updates that occur on all the
EtaPRO screens. EtaPRO provides an intuitive but
powerful means of performing short and long-term
trending. This feature offers numerous options for
selecting and viewing historical data, including use of
data filters to identify steady-state operating periods,
high load operation, or operation near ISO or
POWER-GEN MIDDLE EAST 2010 October 4- 6, 2010 Doha, Qatar
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reference ambient conditions. EtaPRO incorporates
the plant‟s shift schedule to allow comparison of
performance between crews if desired. Custom trends
can be saved as Trend Definitions, incorporating
specific data points, filters, scaling options, trend
colors, etc. and then readily access from the EtaPRO
Client navigation tree. Plant and equipment
performance can be trended and then saved for future
reference as Foot-Prints. This last feature is
especially useful for documenting post-overhaul
performance. As another example, steady-state gas
turbine output at base load operation within a narrow
ambient temperature range can be recovered over a
long period of time to detect output degradation. Data
can be trended by shift or crew and plotted against
time or another parameter. The ability to trend plant
and equipment performance over a long period of
time provides a significant diagnostic capability to
plant personnel. A picture of a typical trend is shown
in Figure 2. For example, if a change in gas turbine
efficiency is sudden, one might suspect mechanical
damage. Conversely, if the change occurs slowly
over time, erosion or deposits may be more likely.
Continuous real-time monitoring and trending allows
the engineer to gain greater insight into the process
than periodic special purpose performance tests.
Lastly, the ability to trend a KPI mitigates the larger
uncertainties associated with plant instrumentation
vs. special purpose test instruments.
Figure 2. EPTrendSetter
Modeling (VirtualPlant™ Software). The modern
power and desalination plant consists of several
components that operate over a wide range of
conditions. For example, the Jebel Ali L1 Plant can
operate from full power and water production (800
MW and 317,500 m3/day, respectively) down to only
enough power to meet auxiliary loads and many
combinations in between. Often new plants such as
Jebel Ali L1 are provided with a limited set of mass
and energy balances against which to compare plant
performance. Therefore, a critical part of any
monitoring system is a first–principles
thermodynamic model. This model integrates all
plant components to: provide expected levels of
equipment and plant performance, evaluate
equipment condition, validate process data, and
quantify the impact of off-design component
performance on overall plant heat rate and capacity.
GP‟s VirtualPlant thermodynamic modeling
framework meets each of these requirements at the
Jebel Ali L1 Plant.
Reporting (EPReporter™). Real-time displays are
valuable for operators and engineers when
monitoring performance or diagnosing equipment
deficiencies. However, many supervisory and
management personnel prefer to have information
pushed to them rather than having to mine or pull the
data themselves. This push vs. pull concept is
implemented using GP‟s EPReporter an automated
reporting tool that distributes MS Excel™ based
reports containing process data and KPIs to printers,
email addresses, and WEB pages. The reporting
process is automated to allow plant personnel to
focus their energies on problem resolution, not
cumbersome reporting tasks. Figure 3 shows the
EPReporter access page.
Figure 3. EPReporter
Problem Diagnosis (Diagnostic Help Charts). The
EtaPRO has the provision for providing assistance to
operators and engineers in diagnosing and resolving
“off-target” performance. Diagnostic Help Charts
provide a methodical approach for detecting the
cause(s) of low steam temperature, low gas turbine
exhaust temperature, low gas turbine compressor
efficiency etc. Each diagnostic incorporates proven
POWER-GEN MIDDLE EAST 2010 October 4- 6, 2010 Doha, Qatar
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operating practices to help guide the operator or
engineer in detecting the root cause of a performance
deficiency.
VIRTUALPLANT OPTIMIZERS
GP‟s VirtualPlant technology, a rigorous first-
principles thermodynamic modeling framework, is
used for many purposes within the Jebel Ali L1
EtaPRO System. Plant models are executed on a real-
time basis to provide expected levels of performance
for the gas and steam turbines, heat recovery steam
generators and desalination trains. In addition, these
same models are used for both off-line and on-line
optimizers.
VirtualPlant models are created in the Cycle Builder,
which contains all the components necessary to
complete the power and water production systems.
Individual components are interconnected through
direction connections with one another. Mixer and
splitter components are used to direct flows as
necessary.
The model is solved by applying the laws of
conservation of mass and energy to each successive
component until the overall model converges within
the user-defined tolerance. Figure 4 shows the Jebel
Ali L1 model.
Real-time Targets. The VirtualPlant models are
configured to run on a continuous real-time basis for
the following four cases:
1. Base Load at Current Conditions
2. Part Load at Current Conditions
3. Base Load at Reference Conditions
4. Part Load at Reference Conditions
Case models are scheduled to run within the
VirtualPlant OPC Server, which acquires model
inputs (ambient and process data) from the EtaPRO
OPC Server. In turn, the EtaPRO Server acquires
model results continuously from the VirtualPlant
OPC Server. This two-way communication is an
effective way to share data between the two
Figure 4. VirtualPlant Cycle Builder (Jebel Ali L1 Power Station)
POWER-GEN MIDDLE EAST 2010 October 4- 6, 2010 Doha, Qatar
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applications. Results from the four cases above are
used to present real-time targets for the EtaPRO
displays as well as to provide correction factors to
allow actual performance to be adjusted to reference
conditions for long-term trending.
On-line Optimization. The VirtualPlant model is
exercised in two ways to provide optimized
equipment settings for a current power and water
production:
1. Equipment Currently In Service.
2. Equipment Available for Service.
Models are executed in the VirtualPlant OPC Server
with results acquired by the EtaPRO System for
presentation to operators on a continuous real-time
basis.
Off-line Optimization. The VirtualPlant “What-If”
provides plant operations personnel, engineers, and
planner with a fully interactive and user-friendly tool
to perform detailed mass and energy balances of the
Jebel Ali L1 Power Plant, (see Figure 5).
The VirtualPlant allows operators to enter ambient
conditions, equipment constraints, water and power
production requirements, top brine temperature, etc.
and then determine the most effective settings for
loading the gas turbines and duct burners to achieve
the desired power and water production. Figure 6
shows the optimizer control panel.
The optimizer control panel allows end-users to
select equipment availability, choose individual
setpoints for gas turbine load, duct burner fuel
consumption, distillate production, and top brine
temperature. Operating constraints such as throttle
pressure and LP turbine exhaust flow are also set in
the control panel. Simple cycle operation as well as
gas turbine base load operation may be selected as
well. The optimizer also offers a Maximize Power
mode in which case the gas turbines and duct burners
are maximized for the ambient conditions while
meeting water production requirements.
The model is capable of giving over fifty different
modes of operations during different operating
conditions of ambient conditions. The model shows
the effect on the overall plant performance
(generation, heat rate and water production) with
different levels of supplementary or without
supplementary firing in the HRSGs. In addition,
detailed information about every component in
Figure 4 is also available.
Figure 5. VirtualPlant Off-line Optimizer
Figure 6. Off-line Optimizer Control Panel
The screen in Figure 4 depicts the full mass and
energy flows to facilitate evaluations of conceptual
changes in operating parameters as well as equipment
design and efficiency improvements if the station so
desired to carry out. The VirtualPlant “What-If” heat
balance is a first principle, rigorous engineering
model that fully integrates individual component
models to simulate the impact of any envisioned
operational or component design changes. Each
component can be rearranged or redesigned to model
and evaluate a variety of different options.
Operating parameters and templates are provided to
facilitate the users input of conceptual changes to the
existing plant design. Operating decisions such as
taking out supplementary firing in HRSGs, reducing
steam temperatures, reducing GT load, removing
desalination units from service etc. can be pre-
evaluated off-line without impacting the operation of
the actual plant with high degree of uncertainty of the
final results. Engineering evaluations, such as impact
of fouling in the desalination units, the use of duct
POWER-GEN MIDDLE EAST 2010 October 4- 6, 2010 Doha, Qatar
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burners in the HRSGs the use of auxiliary boilers in
service can also be evaluated.
The VirtualPlant “What-If” can easily be utilized to
predict the performance of the plant at different
ambient conditions (with or without duct burners of
using gas turbines in simple cycle operation) for
dispatch purposes. The power off-taker normally
requires such information 24 hours before dispatch of
power in real time. This can drastically improve the
plant‟s ability to judge its power, efficiency and
water production capabilities and be very
competitively placed in the stacking order of
dispatch. In addition, the VirtualPlant will be used by
the station to optimize the sale of electricity, water
and steam at different supply and demand criteria.
INFRASTRUCTURE
The hardware and software infrastructures of the
Jebel Ali L1 EtaPRO System consist of standardized
components in a proven design.
Historian. The performance monitoring system is
tightly integrated with OSIsoft® technology,
allowing a direct connection to the DCS for data
acquisition, historical data retrieval, and PI tag
creation or maintenance. The system acquires all
process data (temperatures, pressures, flows, MWs,
etc.) from Jebel Ali‟s historian data base system and
the performance monitoring results are written back
to the historian system.
The performance monitoring system is installed to
allow sharing of performance information with all
levels of plant staff as well as corporate-wide, as
shown in Figure 7 below. The server is connected to
the local area network (LAN) of the Jebel Ali L1
Plant and its wide area network system (WAN). Any
desktop computer running the client application and
allowed access to the Jebel Ali L1 network has full
access to all the features of the performance
monitoring system, including viewing real-time
calculated results and retrieving historical data. The
system is protected through firewalls at strategic
locations. Due to internal security issues the remote
link to GP Support was not available during the
installation of the EtaPRO System and installation
was carried out at site.
Server. The server operates on a dedicated computer
installed by Toshiba/GP. The server acquires field
data, calculates performance, archives historical data,
and provides real-time or historical information to the
workstation "client" applications. The client software
will be used by Jebel Ali L1 users of all levels
including operators, engineers, managers and
supervisors to view or edit (with appropriate
password) the system configuration, displays, and
reports. The performance monitoring system is self-
Plant LAN
PI Server
PI InterfaceBuffer
DCS
Local Plant Clients
EtaPRO Server•EtaPRO Server•EPReporter•EP TrendSetter•PI-API•MS Office•pcAnywhere
DCS Data Highway
WANCorporate Clients
Control Room
PlantManager
Plant Engineer
GP Support (VPN)
Plant LAN
PI Server
PI InterfaceBuffer
DCS
Local Plant Clients
EtaPRO Server•EtaPRO Server•EPReporter•EP TrendSetter•PI-API•MS Office•pcAnywhere
DCS Data Highway
WANCorporate Clients
Control Room
PlantManager
Plant Engineer
GP Support (VPN)
Figure 7. Typical Hardware Arrangement
documenting. Each system is delivered with a series
of reports that describe the system configuration.
The Performance Engine provides a powerful
environment for turning process data into
Performance Information. The performance
monitoring system includes a comprehensive
Performance Calculation Library of over 500 proven
engineering calculations for assessing all types of
equipment and machinery, including gas turbines,
HRSGs, steam turbines, pumps, and desalination
units. Selecting from the extensive Performance
Calculation Library, the user can readily configure
and assess on-line performance of virtually every
major piece of plant equipment.
Client Software. The performance monitoring
software operates on Windows operating systems.
The EtaPRO Client application is used to view real-
time and historical information, and to configure and
maintain the system configuration on the server. The
workstations can update as fast as once every four
seconds, but are typically set for once a minute. Users
can monitor graphical displays, trend plant
parameters, generate reports, and modify the
configuration data (with password protection).
Automated Alerts. The EPAlert™ application
automatically sends a text message when abnormal
conditions occur within the plant. Users receive alerts
when plant status changes (unit trips, start-ups, full
load achieved, etc.). Alerts may be sent to mobile
phones, PDAs, IPAQ‟s, Blackberry®, etc. to notify
the user of plant or equipment changes.
Electronic Operations Log. The Operator Log is
designed to replace the manual log book in the
control room. A significant advantage of using the
EtaPRO Operations Log is that entries are
automatically cross-referenced with process data
trends. Figure 8 shows a typical log page.
POWER-GEN MIDDLE EAST 2010 October 4- 6, 2010 Doha, Qatar
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Figure 8. Electronic Operations Log
INSTALLATION PROCESS
There are several key stages that have to be
systematically carried out prior to the software being
installed on the power plant‟s computers. These are
described here:
1. Collection of all design information supplied by
the Original Equipment Manufacturers (OEMs)
pertinent to the key components installed on the
power station. These include the gas turbines, the
boilers, the steam turbines, the auxiliary boiler
system, the desalination plant and the balance of
plant such as the boiler feed pumps, cooling
water pumps etc. To cover all operating
scenarios, design data is also required at part
loads and any abnormal eventualities.
2. The software model of the power plant at base
load is created using GP VirtualPlant tool. The
model incorporated with full design data is run
with different operating conditions at base load
and tuned to match the OEMs figures at off-
design conditions at base load. This involves
inserting correction factors at base load for all
ranges of operating conditions. The correction
factors include ambient temperature, ambient
pressure, ambient relative humidity, electrical
power factor, cooling water temperature, brine
water temperature etc. These correction factors
will have direct impact on the commodities
which are net revenue for the station. Jebel Ali
L1‟s net monetary revenue streams and
consequently its profitability are based on the
payments for the intake of fuel consumed and the
payment received for the generation of electrical
power and the production of desalination water.
3. Further VirtualPlant models are created to cater
for part load operations. The models created
include all gas turbines at part load operation,
different cases of gas turbine electrical output
including shut down of one or two or three gas
turbines. Cases also include total shut down of
GTs with only the auxiliary boilers and steam
turbine/s in operation for steam generation for
production of desalination water or GTs in
simple cycle operation. All models are tuned to
reflect the design data supplied for the equipment
hardware installed at Jebel Ali L1 Plant.
4. Once the design models are created in
VirtualPlant and match the design data at base
and part loads, the next task involves creating the
models to reflect the actual plant. In order to
replicate the plant „as is‟, actual test data collated
from technical documents and actual operating
conditions is inserted in the VirtualPlant models
and tuned to depict the operating conditions. The
tuning process may involve changing the design
data at this stage as the OEMs could have under
or over estimated the performance of the
hardware. This can be due to commercial,
technical and/or manufacturing/machining
reasons. If the plant was tested at different part
loads the VirtualPlant models are run to compare
the actual figures. The model may be fine tuned
to reflect the actual conditions at these loads. The
GPC‟s VirtualPlant software is also capable of
calculating the „What-If‟ scenarios for this plant.
5. In parallel with the above tasks, the plant‟s
existing hardware and the software DCS is
thoroughly checked for its compatibility with the
Toshiba/GPC‟s hardware and software system
prior to linking it together. The link continues to
the end users and can be used the Operators,
Engineers, Managers, Traders, Planners,
Dispatchers etc. This meticulous job involves
checking the existing station‟s historian and data
collection system. Each tag of the data with its
unique numbering system that is connected to
the DCS Software is checked for its integrity and
connectivity. The tags are used to display direct
readings in engineering units or the engineering
units are used for performance calculations. The
mathematical formula and/or equations are
tailored to meet specific plant criteria and display
screens in the EtaPRO system.
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REAL-TIME PERFORMANCE MODULES
The performance monitoring system provides
engineers and supervisors with a convenient and
efficient means of tracking plant performance. Since
the Jebel Ali L1 Combined Cycle Plant and
desalination plant performance is subject to wide
variation with ambient conditions, component and
overall plant capacity and heat rate must be corrected
to current conditions on a minute-to-minute basis.
The following displays are typical of the Jebel Ali L1
facility, as well as other combined cycle plants
equipment with EtaPRO.
Operator Controllable Parameters. Industry
experience has shown that power plant operators play
a key role in any heat rate improvement program.
The Operator Controllable Parameters, as shown in
Figure 8, provide operators with the information
needed to operate at peak efficiency. A tabular listing
of key controllable parameters such as gas turbine
inlet air filter pressure differential, gas turbine inlet
temperature (for inlet cooling systems), condenser
pressure, cooling water temperature, and compressor
section efficiency are displayed, along with
appropriate “target” values. The performance
monitoring system displays the costs associated with
“off-target” operation, thereby allowing operators to
trade-off the savings of one parameter against another
to achieve optimal performance. A real-time strip
chart useful for detecting drifting performance shows
the deviation of any parameter including plant heat
rate from its target for the past hour. For the engineer,
the performance monitoring system provides the
unique capability to instantly substitute the “design”
values (one mouse click) for “target” values to
determine the cost of operating with deteriorated
equipment (real-time and historical data).
Gas Turbine. As shown in Figure 10, key
performance parameters such as heat rate, capacity,
combustion air flow and exhaust temperature are
corrected to “standard day” conditions to allow direct
comparison with design specifications or acceptance
test performance. This comparison provides
engineers with the information necessary to detect
“off-spec” performance. This module also computes
compressor efficiency and provides operators with
key operating “targets” for current loading and
ambient conditions.
The performance monitoring system monitors actual
gas turbine performance (heat rate, capacity, natural
gas fuel flow, exhaust flow, expander efficiency,
compressor efficiency, etc.) and compares actual
performance to expected performance at current
ambient (temperature, pressure and humidity) and
Figure 9. Operator Controllable Parameters
Figure 10. Gas Turbine Performance
operating conditions (part load, NOx control, etc.). In
addition to expected performance at current
conditions, the performance monitoring system also
has the capability to correct observed performance to
“Standard Reference” conditions.
Heat Recovery Steam Generator. Safely maintaining
optimum plant efficiency requires close attention by
the operating staff for proper coordination of gas
turbine and HRSG operation. The performance
monitoring system provides operators and engineers
with a profile of actual and expected performance
including HRSG efficiency, expected steam
generation and outlet temperatures for each section,
and heat transfer section effectiveness as presented in
Figure 11.
The performance monitoring system monitors actual
HRSG performance (ASME Loss Method efficiency,
input/output efficiency, effectiveness, and pinch
point) and compares this performance to expected
performance at current ambient conditions and
operating conditions. The performance monitoring
system uses a rigorous heat transfer model to predict
expected performance at part load and off-design
conditions. Performance indices of the HRSG, such
POWER-GEN MIDDLE EAST 2010 October 4- 6, 2010 Doha, Qatar
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Figure 11. HRSG Performance
as heat transfer rate, effectiveness, and pinch point
analysis is provided for each HRSG section.
Steam Turbine. The performance monitoring system
calculates actual steam turbine performance (section
enthalpy-drop efficiencies, stage flow factors,
corrected stage pressures, turbine cycle heat rate, and
generator capacity) and compares actual performance
to expected performance at current ambient
conditions and operating conditions as displayed in
Figure 12. The system also has the capability of
calculating individual turbine section power outputs,
low-pressure turbine efficiency by energy balance,
and throttle flow corrected for initial conditions.
Figure 12. Steam Turbine Performance
Desalination Unit Performance. Perhaps more than
any other operating parameter, the performance ratio
of the desalination has the most significant impact on
turbine and the bottoming cycle heat rate. The
desalination performance determines how much
steam is extracted depending on the top and bottom
brine temperature, circulating water flow, tube
cleanliness, heat loading, and the sea water
temperature. Actual performance is compared to
expected values by using a detailed desalination
model to predict the water production under varying
operating conditions as shown in Figure 13.
Figure 13. Desalination Unit Performance
The performance monitoring system uses a detailed
desalination model to estimate design and target
performance for current operating and ambient
conditions such as heat load and circulating water
inlet temperature. Design performance is predicted
using the design parameters, while “target”
performance accounts for fouled desalination unit.
This approach allows the engineer to determine the
cost of operating with fouled unit over the long term.
Target parameters represent achievable performance
for the operating staff based on current equipment
condition.
On-line Optimizer. This application helps operators
identify the most efficient way of running the plant
by looking at the current operating conditions and
comparing that with the equipment that is already in
service and also with the equipment that would be
available. The screen depicts the main component of
the power plant and gives instantaneous picture of the
optimization of the plant in service and plant that is
not running but is available. The On-Line Optimizer
screen is shown in Figure 14.
TECHNOLOGY & OWNERSHIP TRANSFER
Key to achieving improved operation is a unique
combination of state-of-the-art software and
technology transfer through training and mentoring
for the plant operations team. This combination
provided the information needed for improved
information as well as a knowledgeable workforce
that understood how to use the "new" information
and tools to improve operations and business
processes.
Open System. The performance monitoring system is
a full-capability “open system” with extensive
features and capabilities to provide value over the life
of the system. This means that the Jebel Ali L1
Engineering and Operations personnel can expand
the breadth and depth of the performance monitoring
system without additional costs from the vendor. This
transfer is facilitated by use of an extensive library of
POWER-GEN MIDDLE EAST 2010 October 4- 6, 2010 Doha, Qatar
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calculation and equipment design templates, and
workforce training.
Figure 14. On-Line Optimzer
Training & Documentation. The importance of
training and documentation is emphasized to assure
performance monitoring system “transfer of
ownership” as well as acceptance and use of the
performance monitoring system by operating
personnel.
System Administrator Training is a hands-on, in-
depth training session where the Jebel Ali L1
Technical Staff becomes familiar with the
performance monitoring system architecture from a
user-configuration standpoint. The training focuses
on database configuration; Virtual Plant
configuration; owner customizable features such as
developing new screens; scheduling and configuring
automated reports; modifying the data base;
exporting data files to spreadsheets; changing target
values; and troubleshooting tips and procedures. The
documentation describes the overall operation and
hardware configuration details.
User Training is a hands-on program that covers the
use of the system‟s features and capabilities. The
documentation describes the screen displays and how
to access different system capabilities. The User
Training and documentation are presented in English
to assure that all plant personnel accept and use the
performance monitoring system to increase
efficiency, reliability and capacity.
INITIAL RESULTS
Initial study shows that the Jebel Ali L1 Plant
presently has some areas identified for potential
savings. These areas include optimization of
electricity sales with desalination water and
cogeneration loads with HRSG with and without
supplementary firing. Additional plant runtime at
base load conditions is required to establish
performance baselines and check for other potential
savings. Engineering analyses continue with the
results presently being produced from the online
performance monitoring system.
The performance monitoring system will be used for
the following evaluation studies:
Gas turbines operating at different loads and the
impact on power, efficiency, desalination water
production and cogeneration steam supply
Use of duct burners when gas turbines are out of
service
Optimization of evaporative coolers
Optimization of the balance of plant including
the desalination system
Final results of these evaluation studies will be
presented later.
REFERENCES
1. DesJardins & Novelli, Global Generating Asset
Management Using Real-time Performance
Monitoring and Reporting, PowerGen
International 2002, Orlando, FL, USA.
2. DesJardins, Daycock & Fennell, Generation
Cost Forecasting Using On-line Thermodynamic
Models, Electric Power 2004, Baltimore, MD,
USA.
3. DesJardins, Daycock & Kram, Forecasting
Asset Performance Using Real-time
Thermodynamic Models, PowerGen International
2004, Orlando, FL, USA.
4. DesJardins, Parmar, Yang & Zafar, Real-time
Performance Monitoring & Optimization at Ras
Laffan Power Company’s Combined Cycle
Power and Desalination Plant in Qatar,
PowerGen Middle East 2007, Manama, Bahrain.
ACKNOWLEDGEMENT
GP is very grateful to all Jebel Ali Operation Staff for
all their cooperation given during the successful
handover of the EtaPRO System to DEWA. GP wish
to thank all Toshiba staff who assisted in the
installation of the EtaPRO System at Jebel Ali L1
Power Station.